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3 years ago

Which of these is a pure substance? A) a penny B) Sugar C) ocean water D) iced tea

2 answers:

8 0

Heyo,

Sugar is a pure substance. A pure substance is a substance that has chemical properties. Sugar is a pure substance.

s2008m [1.1K]3 years ago

5 0

B. Sugar
It is sugar because sugar is made up of one atom or molecule.
A) penny is not correct because a penny is made up of copper, zinc, and tin.
C) ocean water is not correct because its made out of water (h2o) and salt.
D) iced tea is not correct because it takes many atoms to combine in order to make tea, then you have to add water and ice to make it an iced tea.
Hope this helps!! :)

You might be interested in

hydrogen decomposes quickly when exposed to light. the reaction for decomposing hydrogen peroxide is:

Svet_ta [14]

The decomposition reaction for hydrogen peroxide is given below:

2 $H_{2}$ $O_{2}$ → 2 $H_{2}$ O + $O_{2}$

This is a decomposition reaction.

Reactions in which a reactant breaks into two or more products are known as Decomposition reactions.

AB → A + B

here, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction

The decomposition reaction of decomposing hydrogen peroxide is exothermic. When the hydrogen peroxide undergoes a decomposition reaction, heat is also released along with water and oxygen.

Hence the reaction for decomposing hydrogen peroxide is :

2 $H_{2}$ $O_{2}$ → 2 $H_{2}$ O + $O_{2}$

If you need to learn more about Decomposition reaction, click here

brainly.com/question/16987748?

#SPJ4

5 0

1 year ago

I need this ASAP i will give brainliest :)

shutvik [7]

Answer:

I really dont know i just guessed :(

Explanation:

5 0

3 years ago

For Na2HPO4:(( (Note that for H3PO4, ka1= 6.9x10-3, ka2 = 6.4x10-8, ka3 = 4.8x10-13 ) a) The active anion is H2PO4- b) The activ

Komok [63]

Answer:

Check the explanation

Explanation:

Answer – Given, $H_3PO_4$ acid and there are three Ka values

$K_{a1}=6.9x10^8, K_{a2} = 6.2X10^8, and K_{a3}=4.8X10^{13}$

The transformation of $H_2PO_4- (aq) to HPO_4^2-(aq)$ is the second dissociation, so we need to use the Ka2 = 6.2x10-8 in the Henderson-Hasselbalch equation.

Mass of KH2PO4 = 22.0 g , mass of Na2HPO4 = 32.0 g , volume = 1.00 L

First we need to calculate moles of each

Moles of KH2PO4 = 22.0 g / 136.08 g.mol-1

= 0.162 moles

Moles of Na2HPO4 = 32.0 g /141.96 g.mol-1

= 0.225 moles

[H2PO4-] = 0.162 moles / 1.00 L = 0.162 M

[HPO42-] = 0.225 moles / 1.00 L = 0.225 M

Now we need to calculate the pKa2

pKa2 = -log Ka

= -log 6.2x10-8

= 7.21

We know Henderson-Hasselbalch equation

pH = pKa + log [conjugate base] / [acid]

pH = 7.21 + log 0.225 / 0.162

= 7.35

The pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L is 7.35

6 0

3 years ago

Which of the following is a change of state?

Step2247 [10]

Answer:

I think C. Hope this Helps!

Explanation:

5 0

3 years ago

The atomic number of lead (Pb) is 82. Its mass number is 207. How many protons, neutrons, and electrons does this neutral atom o

AveGali [126]

An element’s atomic number is equal to the number of protons in that element’s nucleus. The mass number is the total number of an atom’s protons and neutrons. Protons have a positive charge; electrons have a negative charge; and neutrons are electrically neutral.

Putting it all together, given that the atomic number of lead is 82, the number of protons a lead atom contains is 82. The number of neutrons would be the difference between 207 and 82, or 125 neutrons. Finally, since you have a neutral atom, there must be an equal number of electrons as the number of protons—that is, 82 electrons.

Thus, you’ve got 82 protons, 125 neutrons, and 82 electrons.

7 0

3 years ago